公开(公告)号：US06307368B1

公开(公告)日：2001-10-23

申请号：US09312025

申请日：1999-05-14

申请人： Shreyas S. Vasanawala ,  John M. Pauly ,  Dwight G. Nishimura

发明人： Shreyas S. Vasanawala ,  John M. Pauly ,  Dwight G. Nishimura

IPC分类号： G01V300

CPC分类号： G01R33/5613 ,  G01R33/446

摘要： A fast, spectrally-selective steady-state free precession (SSFP) imaging method is presented. Combining k-space data from SSFP sequences with certain phase schedules of radiofrequency excitation pulses permits manipulation of the spectral selectivity of the image. For example, lipid and water can be rapidly resolved. The contrast of each image depends on both T1 and T2, and the relative contribution of the two relaxation mechanisms to image contrast can be controlled by adjusting the flip angle. Several applications of the technique are presented, including fast musculoskeletal imaging, brain imaging, and angiography. The technique is referred to herein as linear combination steady-state free precession (LCSSFP) and fluctuating equilibrium magnetic resonance (FEMR).

摘要翻译： 提出了一种快速，频谱选择性的稳态自由进动（SSFP）成像方法。 将来自SSFP序列的k空间数据与射频激发脉冲的某些相位调度组合允许操纵图像的光谱选择性。 例如，脂质和水可以快速解决。 每个图像的对比度取决于T1和T2，并且可以通过调整翻转角度来控制两个松弛机制对图像对比度的相对贡献。 提出了该技术的几个应用，包括快速肌肉骨骼成像，脑成像和血管造影。 该技术在此被称为线性组合稳态自由进动（LCSSFP）和波动平衡磁共振（FEMR）。

公开(公告)号：US08638096B2

公开(公告)日：2014-01-28

申请号：US12907764

申请日：2010-10-19

申请人： Tao Zhang ,  Michael Lustig ,  John M. Pauly ,  Shreyas S. Vasanawala

发明人： Tao Zhang ,  Michael Lustig ,  John M. Pauly ,  Shreyas S. Vasanawala

IPC分类号： G01R33/56

CPC分类号： G01R33/5611 ,  G01R33/4824

摘要： A computer implemented method for magnetic resonance imaging is provided. A 3D Fourier Transform acquisition is performed with two phase encode directions, wherein phase code locations are chosen so that a total number of phase encodes is less than a Nyquist rate, and closest distances between phase encode locations takes on a multiplicity of values. Readout signals are received through a multi-channel array of a plurality of receivers. An autocalibrating parallel imaging interpolation is performed and a noise correlation is generated. The noise correlation is used to weight a data consistency term of a compressed sensing iterative reconstruction. An image is created from the autocalibration parallel imaging using the weighted data consistency term. The image is displayed.

摘要翻译： 提供了一种用于磁共振成像的计算机实现方法。 使用两个相位编码方向执行3D傅立叶变换采集，其中选择相位位置使得相位编码的总数小于奈奎斯特速率，并且相位编码位置之间的最近距离具有多个值。 通过多个接收器的多通道阵列接收读出信号。 执行自动校准并行成像内插，并产生噪声相关。 噪声相关用于加权压缩感测迭代重建的数据一致性项。 使用加权数据一致性项从自动校准并行成像创建图像。 显示图像。

公开(公告)号：US08538115B2

公开(公告)日：2013-09-17

申请号：US13211905

申请日：2011-08-17

申请人： Tao Zhang ,  Michael Lustig ,  Shreyas S. Vasanawala ,  John M. Pauly

发明人： Tao Zhang ,  Michael Lustig ,  Shreyas S. Vasanawala ,  John M. Pauly

IPC分类号： G06K9/00 ,  G06K9/32

CPC分类号： G01R33/5611

摘要： A three dimensional image, in a phased array magnetic resonance imaging (MRI) system is provided. Three dimensional k-space data within an auto calibration signal (ACS) region and outside the ACS region are acquired. The k-space data within the ACS region are converted into hybrid space ACS data. Compression matrices and alignment matrices of the compression matrices for the hybrid space ACS data are found along a readout direction. Alignment matrices are multiplied to the compression matrices to achieve the properly-aligned compression matrices along the readout direction. All k-space data are converted into hybrid space. The properly-aligned compression matrices are applied to the hybrid space data to provide compressed data with fewer channels. The compressed data are used to form a three dimensional image.

摘要翻译： 提供了在相控阵磁共振成像（MRI）系统中的三维图像。 获取自动校准信号（ACS）区域和ACS区域之外的三维k空间数据。 ACS区域内的k空间数据被转换为混合空间ACS数据。 沿着读出方向找到用于混合空间ACS数据的压缩矩阵的压缩矩阵和对准矩阵。 对齐矩阵与压缩矩阵相乘以便沿着读出方向实现正确对齐的压缩矩阵。 所有k空间数据都转换为混合空间。 将适当对齐的压缩矩阵应用于混合空间数据，以提供具有较少信道的压缩数据。 压缩数据用于形成三维图像。

公开(公告)号：US06806708B1

公开(公告)日：2004-10-19

申请号：US10464296

申请日：2003-06-17

申请人： Jin Hyung Lee ,  John M. Pauly ,  Dwight G. Nishimura

发明人： Jin Hyung Lee ,  John M. Pauly ,  Dwight G. Nishimura

IPC分类号： G01V300

CPC分类号： G01R33/5611

摘要： Imaging time using PILS is reduced by using multiple coils with localized sensitivities with each coil having a separate demodulation channel thereby permitting parallel signal processing and image reconstruction. Images from the multiple coils are then combined to form an image with a larger field of view (FOV).

摘要翻译： 使用PILS的成像时间通过使用具有局部灵敏度的多个线圈来减少，每个线圈具有单独的解调信道，从而允许并行信号处理和图像重建。 然后将来自多个线圈的图像组合以形成具有较大视场（FOV）的图像。

公开(公告)号：US5150053A

公开(公告)日：1992-09-22

申请号：US645859

申请日：1991-01-25

申请人： John M. Pauly ,  Steven M. Conolly ,  Dwight G. Nishimura

发明人： John M. Pauly ,  Steven M. Conolly ,  Dwight G. Nishimura

IPC分类号： A61B5/055 ,  G01R33/48 ,  G01R33/50 ,  G01R33/56 ,  G01R33/561

CPC分类号： G01R33/446 ,  G01R33/50 ,  G01R33/56

摘要： Magnetic resonance signals for imaging species having short spin-spin relaxation times (T.sub.2) are obtained without the need for a refocusing lobe. A series of RF excitation pulses are applied to the species with magnetic resonance signals being detected after each RF excitation pulse is applied. The magnetic resonance signals are then combined to provide the imaging signals. In one embodiment, each RF excitation pulse is half of a conventional slice-selective pulse with each pulse being slewed to zero. Contrast between the imaged short T.sub.2 species and longer T.sub.2 species can be enhanced by first applying an RF signal having sufficient amplitude to excite the longer T.sub.2 species but insufficient amplitude to excite the short T.sub.2 species whereby the longer T.sub.2 species are tipped by the RF signal. A magnetic gradient can then be applied to dephase the tipped nuclei of the longer T.sub.2 species. The imaging signals are then obtained from magnetic resonance signals from the short T.sub.2 species.

摘要翻译： 获得具有短自旋 - 自旋弛豫时间（T2）的成像物质的磁共振信号，而不需要重新聚焦波瓣。 在施加每个RF激励脉冲之后，对具有磁共振信号的物种施加一系列RF激励脉冲。 然后将磁共振信号组合以提供成像信号。 在一个实施例中，每个RF激励脉冲是常规切片选择脉冲的一半，其中每个脉冲被转换为零。 可以通过首先施加具有足够振幅的RF信号来激发较长的T2物种但不足的幅度来激发短的T2物种，从而通过RF信号使更长的T2物种倾斜，可以增强成像的短T2物种与较长的T2物种之间的对比。 然后可以应用磁梯度来去除较长T2物种的尖端核。 然后从来自短T2物种的磁共振信号获得成像信号。

公开(公告)号：US07277597B2

公开(公告)日：2007-10-02

申请号：US10464236

申请日：2003-06-17

申请人： Jin Hyung Lee ,  John M. Pauly ,  Dwight G. Nishimura

发明人： Jin Hyung Lee ,  John M. Pauly ,  Dwight G. Nishimura

IPC分类号： G06K9/36

CPC分类号： G01R33/4824 ,  G01R33/561

摘要： A modified projection on convex sets (POCS) algorithm and method for partial k-space reconstruction using low resolution phase maps for scaling full sets of reconstructed k-space data. The algorithm can be used with partial k-space trajectories in which the trajectories share a common point such as the origin of k-space, including variable-density spiral trajectories, projection reconstruction trajectories with a semicircle region acquisition, and projection reconstruction trajectories with every other spike acquired.

摘要翻译： 使用低分辨率相位图进行局部k空间重建的凸集（POCS）算法和方法的改进投影，用于缩放全套重建的k空间数据。 该算法可以与部分k空间轨迹一起使用，其中轨迹共享公共点，例如k空间的起点，包括可变密度螺旋轨迹，具有半圆区域获取的投影重建轨迹，以及每个 其他穗获得。

公开(公告)号：US5025216A

公开(公告)日：1991-06-18

申请号：US386901

申请日：1989-07-28

申请人： John M. Pauly ,  Dwight G. Nishimura

发明人： John M. Pauly ,  Dwight G. Nishimura

IPC分类号： G01R33/48 ,  G01R33/50 ,  G01R33/561

CPC分类号： G01R33/446 ,  G01R33/50

摘要： Magnetic resonance signals for imaging species having short spin-spin relaxation times (T.sub.2) are obtained without the need for a refocusing lobe. A series of RF excitation pulses are applied to the species with magnetic resonance signals being detected after each RF excitation pulse is applied. The magnetic resonance signals are then combined to provide the imaging signals. In one embodiment, each RF excitation pulse is half of a conventional slice-selective pulse with each pulse being slewed to zero.

摘要翻译： 获得具有短自旋 - 自旋弛豫时间（T2）的成像物质的磁共振信号，而不需要重新聚焦波瓣。 在施加每个RF激励脉冲之后，对具有磁共振信号的物种施加一系列RF激励脉冲。 然后将磁共振信号组合以提供成像信号。 在一个实施例中，每个RF激励脉冲是常规切片选择脉冲的一半，其中每个脉冲被转换为零。

公开(公告)号：US5957843A

公开(公告)日：1999-09-28

申请号：US515090

申请日：1995-08-14

申请人： Gerard T. Luk Pat ,  Craig H. Meyer ,  John M. Pauly ,  Dwight G. Nishimura

发明人： Gerard T. Luk Pat ,  Craig H. Meyer ,  John M. Pauly ,  Dwight G. Nishimura

IPC分类号： G01R33/561 ,  A61B5/055

CPC分类号： G01R33/5615 ,  G01R33/5616

摘要： Flyback imaging is combined with echo planar imaging (EPI) for improved readout flow properties. For increases in imaging time of 50% or less, significant improvements in imaging are realized. The partial flyback improves partial-Fourier EPI and inside-out EPI and can be applied to any EPI trajectory.

摘要翻译： 反激成像与回波平面成像（EPI）相结合，可提高读数流动特性。 对于50％以下的成像时间的增加，可以实现成像的显着改善。 部分回扫提高了部分傅里叶EPI和内向外EPI，并且可以应用于任何EPI轨迹。

公开(公告)号：US5588431A

公开(公告)日：1996-12-31

申请号：US516243

申请日：1995-08-17

申请人： Sanjay Mani ,  Dwight G. Nishimura ,  Steven M. Conolly ,  John M. Pauly

发明人： Sanjay Mani ,  Dwight G. Nishimura ,  Steven M. Conolly ,  John M. Pauly

IPC分类号： A61B5/026 ,  G01R33/563 ,  A61B5/055

CPC分类号： G01R33/5635 ,  A61B5/0263 ,  G01R33/5602

摘要： Multiple inversion recovery flow imaging employs at least four spin inversion pulses following saturation of static nuclei spins to null nuclei in static material having different spin-lattice relaxation times (T.sub.1) with the inversion pulses being spaced in time to substantially reduce the longitudinal magnetization of the T.sub.1 species present. The saturation of static nuclei spins includes applying a sequence of saturation pulses with adjacent pulses being separated by a diphasing gradient to avoid refocusing coherence. The detection of signals includes applying at least one RF read-out pulse near the nulling point.

摘要翻译： 多反转恢复流成像在静态核自旋饱和之后采用至少四个自旋反转脉冲，使具有不同自旋晶格弛豫时间（T1）的静态材料中的零核，其中反转脉冲在时间上间隔开，从而基本上减小了 T1种存在。 静态核自旋的饱和度包括施加饱和脉冲序列，其中相邻脉冲被双相梯度分离以避免重新聚焦相干。 信号的检测包括在零点附近应用至少一个RF读出脉冲。

公开(公告)号：US06452387B1

公开(公告)日：2002-09-17

申请号：US09801424

申请日：2001-03-07

申请人： Brain A. Hargreaves ,  Shreyas Vasanawala ,  John M. Pauly ,  Dwight G. Nishimura

发明人： Brain A. Hargreaves ,  Shreyas Vasanawala ,  John M. Pauly ,  Dwight G. Nishimura

IPC分类号： G01V300

CPC分类号： G01R33/5613

摘要： A steady-state condition for tipped nuclear spins is accelerated or catalyzed by first determining magnetization magnitude of the steady state and the scaling magnetization along one axis (Mz) to at least approximate the determined magnetization magnitude. Then the scaled magnetization is rotated to coincide with a real-valued eigenvector extension of the tipped steady-state magnetization. Any error vector will then decay to the steady-state condition without oscillation. In one embodiment, the magnetic resonance imaging utilizes steady-state free precession (SSFP). The scaling and rotating steps are followed by the steps of applying read-out magnetic gradients and detecting magnetic resonance signals from the tipped nuclear spins. The magnetization magnitude is determined by eigenvector analysis, and the eigenvector extension is a real-valued eigenvector determined in the analysis.

摘要翻译： 通过首先确定稳态的磁化强度和沿着一个轴（Mz）的缩放磁化强度至少接近确定的磁化强度，来加速或催化尖端核自旋的稳态条件。 然后，缩放的磁化被旋转以与尖端稳态磁化的实数特征向量延伸一致。 任何误差矢量都会衰减到稳态，而不会产生振荡。 在一个实施例中，磁共振成像利用稳态自由进动（SSFP）。 缩放和旋转步骤之后是应用读出磁梯度并从尖端核自旋检测磁共振信号的步骤。 磁化强度由特征向量分析确定，特征向量扩展是在分析中确定的实值特征向量。